It's neglect (which is considered a lesser form of child abuse in law).
Failing to provide for your child's material needs is neglect. If I, as a resident parent, did that SS would quickly step in. If non-resident parents are keen to be taken as seriously as the resident parent in terms of their value to the child then they need to take the responsibilities as seriously as the rights.
There are few people who have genuine reasons for non-payment of maintenance. Even those on benefits are considered able to pay a nominal amount of £5 per week.
There are 2.5 million single parents in the UK. 1.15 million of them use the CSA to settle maintenance. Of that 1.15 million, 861,700 of them pay. Of the 861,700 that are paying nearly half (47.3%) are only paying £5 per week (regardless of how many children they have) because they are on benefits. Of the remaining 1.35 million single parent families, 60% have no maintenance arrangements according to the DWP.
Are all these non-maintenance payers starving? Or is it more likely that many of them simply don't want to?
I have no patience with the "why should I pay when she won't let me see the kids" argument. How is punishing the child going to help? Because that's what happens when you with-hold maintenance. Rent, council tax, utilities, food still have to be paid for. If there is no maintenance there is a reduced amount available to cover these things, meaning at best that the child will have to go without luxuries/trips/activities, and at worst that they are losing out on clothing and food. Some RPs love this, of course, because they see it as depriving the RP of luxuries and they can then swan in and buy DC expensive presents that the RP cannot afford because she is too busy spending her money on essential things like food.
The child has a right to contact. How is repeatedly failing to turn up/altering dates at the last minute anything to do with what's best for the child? It isn't. It teaches the child that they don't matter that much. It's cruel. At least with a completely absent father there is no raising of hopes and expectations which are then truly crushed, time after time after time. A resident parent can be imprisoned for unfairly blocking contact. There are no such consequences for non-resident parents who consistently mess about with or miss contact altogether.
Contact and maintenance are not linked but payment is a good indication of whether a person is a fit parent. Unless you can PROVE that your income is so low as to make ANY payment impossible, what possible justification is there? If there isn't one then you are clearly not someone who can put a child's best interests before your own, and in that case is contact actually that desirable?
There was a link on here a while back to a govt. sponsored report about reasons why contact breaks down. While I would never deny that there are some RPs out there who use contact to punish the other spouse, the main thing that came out is that very few parents stop contact out of spouse. Concerns about quality of care and messing about of contact schedules were overwhelmingly the main reasons cited.
Yet despite that, we're still demonising single mothers and making it harder for them to get maintenance by charging to use the CSA and taxing the proceeds.